Toilet bowl venting systems have been known for quite some time. The original type of such venting system included biasing means (e.g. a motor driven fan) for biasing air flow from the bowl of a toilet, through its water tank, and out to a remote point. Usually, these known systems required that the water tank lid be sealed by a sealing gasket, and that a bore be made through the porcelaine body of the water tank: see U.S. Pat. No. 5,029,346 issued Jul. 9, 1991 to Robert FERNALD. Clearly, such an arrangement is unsatisfactory, because the tank body must be broken, to make way for the stale air outlet pipe, and must be modified to accommodate a sealing gasket about its lid.
U.S. Pat. No. 4,153,956 issued May 15, 1979 to Raymond jr and Raymond sr FISCHER, discloses a toilet deodorizing apparatus, showing the concept of hanging an air fan to a panel which rests on the top of a WC water tank, so as not to need to physically alter the cover. In this patent, a plate 16 is provided to support the stale air processing unit 12 spacedly over water level in the tank. It is understood that plate 16 is in fact a diaphragm which is sealed along the periphery of the tank T by a frame 18 and this air filtering diaphragm is gaz permeable. Hence, the stale air is not evacuated but rather processed (i.e. filtered) through an air scrubbing device, to be thereafter returned into the room. The unit 12 includes a fan and a heater, the latter disposed at the outlet of the blower for deodorizing the stale air by the application of extreme heat. The thus purified air is then directly evacuated into the room, the cover C being raised by the spacer members 20, as illustrated in FIG. 2 of this patent.
In other known devices, there is disclosed charcoal-based air filtration means for processing stale air from WC: see for instance the following U.S. Pat. Nos.:
4,031,574 PA0 4,583,250 PA0 5,231,705
This is not cost-effective.
Still other devices require that a suction assembly be installed into the wall, ceiling or flooring of a room, thus introducing large installation costs, not to speak of safety hazards including fire hazards.